The present invention relates to the actuation of electrical switches and, particularly, to enhancing the utility of radius actuators designed to be mounted on a hinged member for selectively engaging a safety switch. More specifically, this invention is directed to an improved radius actuator having a key pivotally mounted relative to a holder for adjustment of a key pivot angle with a setscrew, wherein the key is spring-pretensioned to an insertion position against the setscrew. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.